Underwater breathing regulators



April 1957 J. w. ARPIN UNDERWATER BREATHING REGULATORS 2, Sheets-Sheet 1 Filed Jun 21, 1954 IN V EN TOR.

April 2, 1957 J. w. ARPIN UNDERWATER BREATHING REGULATORS Filed Ju ne 21, 1954 2 Sheets-Sheet 2 IINVENTOI? UNDERWATER BREATHING REGULATORS John W. Arpin, Miami, Fla.

Application June 21, 1954, Serial No. 438,070

15 Claims. (Cl. 137-63) This invention relates to breathing equipment and it is particularly described in connection with a self-contained underwater breathing device. This application is a continuation in part of my prior application Serial No. 372,306, filed August 4, 1953, now Patent No. 2,682,871, issued July 6, 1954.

In my above mentioned prior application, I illustrated and described a breathing regulator used in conjunction with a source of breathable gas such as air. The regulator permits the inspiration of a required quantity of compressed air from a tank containing the air and provides means for exhaling exhaust air into the water. The regulator of the above mentioned application was of novel construction and, in addition, special means were shown for facilitating breathing without risking the loss of breathable gas through the exhaust valve.

The instant application is an improvement over my prior application in that an air reserve device is incorporated into the regulator and the article further assumes extremely simplified form in many respects.

An air reserve device is useful in indicating to a diver that his supply of air has fallen to a predetermined amount and that he has a limited time to rise to the surface or take other appropriate action. Usually, he then operates a control which makes available a small supply of air enabling him to surface Without risk. Such devices have been known per se but they generally have been relatively complex, disposed on the tank, or otherwise objectionable such as, for example, being unreliable in action. Further, to my knowledge, they were inadequate as will be explained hereinafter.

The device of the instant invention has a most meritorious feature in that the air reserve automatically adapts itself to varying conditions of depth or individual demand. For example, an air reserve device which issues a warning when the air in the tank falls to a predetermined pressure, is inadequate because such pressure may represent available air for one minute when the diver is twenty feet down in the water but it may represent only a few seconds of available air at a much greater depth. Accordingly, a fixed signal or the like is somewhat illusory and deceptive. In fact, it may well be considered dangerous since, it may give the diver a false sense of security. It may also be observed that a quantity of air at 600 lbs. pressure, for example, may serve one diver for one minute at a given depth but it may be insufficient for such time for another diver with a higher intake rate. With my invention, however, the device will react sooner if the diver goes to a greater depth and its action is to a large extent independent of the tank pressure but it actually dependent on the divers demands in relation to the tank pressure as will be shown hereinafter. In other words, the warning signal will be given at varying tank pressures depending on the depth reached or other varying demand requirement. This feature renders the device safe and reliable under the conditions above recited. Moreover, notwithstanding the considerable benefits derived from the device, the construction thereof is of exnited States Patent ice treme simplicity, a condition which is highly desired in apparatus of the type under consideration.

The invention will be further understood from the following description and drawings in which:

Figure 1 is a top plan view of the regulator, partly broken away to show construction;

Figure 2 is a cross-sectional view as taken along the line 2-2 of Figure 1;

Figure 3 is a cross-sectional view as taken along the line 3-3 of Figure 2;

Figure 4 is a view similar to Figure 3 with the valve opened to admit air;

Figure 5 is a cross-sectional view taken along the line 5-5 of Figure 3;

Figure 6 is an enlarged cross-sectional view taken along the line 6-6 of Figure 2;

Figure 7 is a View taken along the line 7-7 of Figure 6;

Figure 8 is a view taken along the line 8-8 of Figure 3;

Figure 9 is a view taken along the line 9-9 of Figure 1; and

Figure 10 is a cross-sectional View of a. modification.

As stated and illustrated in my prior patent application, the regulator is used in conjunction with one or more tanks or cylinders containing a supply of compressed air. The tank is strapped to the body of the user and a corrugated rubber tube 10, shown partially herein, is connected to the inhale and exhale tubes 11 and 12 respectively. Centrally of the tube is a breathing mouthpiece, not shown. The regulator usually rests on the back of the wearers neck with the rubber tube substantially encircling his neck. An exhaust valve 13 of the conventional rubber flapper type is affixed to tube 12 and extends inwardly.

The regulator may assume the general form of a disk and comprises a main body 14 which may be a metal casting if preferred. It is formed with two channels 15 and 16, channel 15 being totally enclosed apart from outlet opening 17 and serving as an exhaust chamber in which exhaust valve 13 is disposed. Channel 16 is adapted to communicate both with the source of compressed air and with inhale tube 11 so as to deliver such air to the lungs of the user upon demand as will be shown hereinafter.

The regulator body 14 is formed with a central, screw threaded opening 18 in which air inlet screw ,fitting 19 is disposed. Fitting 19 has a head 20 and two axially aligned hollow chambers 21 and 22 communicating with each other through throat 23 (Figures 3 and 4). Front chamber 21 has disposed therein a high pressure block 24 having a hollow interior 25 serving as a housing and seat for spring 26.

Block 24 is substantially square in transverse crosssection but the corners thereof are rounded in order to be slidably received in chamber 21. The straight sides thereof, between the rounded corners, permit air to flow upwardly in chamber 21 and through throat 23 as will hereinafter be described. The top face of block 24 is substantially planar and is provided centrally with a depressed conical valve seat 27 surrounded by a smooth, hard plastic washer 28 which may be of Teflon or the like.

The floor 29 of chamber 2i is formed with an annular boss 30 which forms part of a valve structure and is adapted to seat against washer 28 so as to close ofi chamber 21 from throat 23. The valve. structure further comprises a valve body 31 which is also substantially square in cross-section with rounded corners. Valve body 31 is provided with a valve pin 32 which is disposed in throat 23 and rests in valve seat 27.

Valve body 31 is bevelled down to a upper edge 33 for facilitating actuation by a lever arm 34 as .will here inafter be described. In order to maintain block 24 and spring 26 in housing 21, a perforated disk 35 is provided at the outlet ofchamber 21. Such disk is maintained in place by a conventional C-shaped spring clip 36 which normally fits into an annular recess and maintains the parts in place.

As was set forth in my prior application, when the device is used for underwater breathing, the pressure of the surrounding water acts upon a movable diaphragm so as to depress it downwardly and actuate a valve accordingly. The valve action is such as to admit air under pressure to the underside of the diaphragm so as to restore it to its normal position by opposing the force of the water pressure. The valve is thus closed when the diaphragm is forced back by the air pressure. The air restoring the diaphragm to normal position isthat which is breathed by the user and is substantially equal to the water pressure at that point. This action will now be described.

Body 14 is formed with an annular wall 40 and an upper face 41. The top of wall 40 is formed with a peripheral head 42. Wall 40 and head 42 serve to support the rubber diaphragm 43. Diaphragm 43 is substantially cup-shaped and of live rubber. The side 44 thereof is annular and its outer edges embrace head 42 and wall 40, being secured thereagainst by a band 45. The planar, disk-shaped face 46 is laminated on both sides thereof with metal disks 47 and 43 so as to present a sturdy planar surface which is nevertheless displaceable downwardly by virtue of the resilient sides 44 of the diaphragm.

Body 14. is. further formed with a flange 49 having an L-shaped periphery adapted to securely support outer cup 50. Cup 50 may be referred to as a can, it being of metal (although it may be of plastic), and enclosing the diaphragm structure. It forms a chamber 51 between the diaphragm and the can and it is provided with a series of upper openings 52 which serve two purposes, i. e., the admission of water to the top face of the diaphragm for subjecting it to water pressure and the outlet means for exhaust air as will hereinafter be described.

The cup-shaped diaphragm structure 43 forms a chamber 55 between it and the upper face 41 of the body 14. It is in this chamber that the compressed air is made available for breathing by the user. This is brought about by a simplified motion transmitting lever action which will now be described.

Body 14 is formed with a ledge 60 which supports rockable lever 61. Lever 61 is formed with two parallel arms 62 and 63 connected by a back 64. The arms 62 and 63 extend upwardly at an angle from back 64 as. illustrated in Figure 2. Back 64 is formed with a hinge pin 65 which rests on ledge 60. In order to maintain the lever back 64 correctly positioned on ledge 60, a plate 66 is screwed down by screws 67 on ledge 60. A central protuberance 68 accommodates the hinge pin 65. The lever structure 61 is terminated at its free outer end by lips 70 on both arms which slidably abut disk 48 so that the lever is adapted for substantially vertical movement in response to movement of diaphragm structrue 43.

A second lever, i. e., lever 34 is provided as was hereinabove mentioned. Lever 34 is channel-shaped and is formed with two transverse protuberances 76 and 77 adjacent the respective ends thereof. Protuberance 77 rests against the top, substantially knife-shaped upper edge 33 of valve body 31. The outer end 78 of lever 34 rests against an adjustable screw 79 which serves as a fulcrum for lever 34. The position of this fulcrum is adjustable for varying the effective action of the lever 34.

The opposite end 80 of lever 34 rests upon a rod 81, the important purposes of which will be hereinafter described. Thus, in effect, lever 34 rests upon rod 81 and valve body 31, and its outer end abuts screw 79.

Lever 34 transmits the motion of lever structure 61 to the valve body 31 so as to admit air under pressure into chamber 55. Such transmission is efiected by the substantially downward movement of lever back 64 as it rocks in response to diaphragm pressure so that it bears against protuberance 76 and pushes the corresponding end of lever 34 downwardly whereupon end '78 bears against screw '79 and produces considerable pressure by protuberance 77 against valve body 31. This action will be found to exert this considerable pressure in a small space so as to minimize the bulk of the regulator.

Downward movement of protuberance '77 moves valve body 31 from the position shown in Figure 3 to the position shown in Figure 4. As was noted, air cannot flow through chamber 21 in the position of Figure 3 because the boss 30 blocks off communication. On the other rand, when valve body 31 is pressed downwardly, the valve pin 32 travels downwardly in throat 23 and depresses block 24 against the action of spring 26. Accordingly, air, as will hereinafter be shown, is permitted to enter through perforated disk 35, travel upwardly along the square sides of block 24, enter throat 23 into chamber 22 and thence to body chamber 55.

The action of the air reserve device will now be described.

This-action employs the principle of limiting the action of the levers in opening the valve as hereinabove described.

Depressing block 24 by the action of the valve body produces an annular opening below boss 30 which establishes communication between the chambers 21 and 22. If the valve pin 32 is depressed downwardly sufficiently to provide a clearance equal to the effective opening of throat 23, a maximum flow of air will result. On the other hand, if the downward movement of the pin is limited, a restriction will be produced which may satisfactorily pass ail-when the tank pressure is high but which may become inadequate to meet the demand when the air pressure is low. In an operating model, a downward movement of the pin .013 inch produced an opening which was substantially equal to the effective opening of throat 23, thus producing maximum flow. However, if the stroke of the levers was limited, the movement of pin 32 is correspondingly limited as will be evident.

As an example, the downward movement of the valve pin may be limited to about .003 inch. In this condition, when the tank pressure is sufliciently high, i. e., over 600 to 2,000 lbs., the pressure is still sufficient to force a normal lung full of air through the restricted opening in a normal length of time under normal conditions at usual depths. However, when the pressure falls to a low level relative to the demand, such pressure is not high enough to provide a normal lung full of air in the normal length of time. This causes the diver to labor with his breathing because his lungs are not filling rapidly enough. It can be seen therefore that with the restricted opening a pressure of 600 lbs. might be satisfactory were the diver to be at a depth of twenty feet. If the diver goes down to forty feet, the demand becomes greater and the restriction may now cause his breathing to become difficult.

Employing the above concept, I have devised means for producing a normally limited movement of the valve body 31 so that the consequent restriction will produce breathing difficulty when the tank pressure falls too low relative to the demand. I further provide means for manually establishing complete opening at this time so that the diver is supplied with the required air but he is apprised of the fact that the remaining pressure is inadequate to permit him to remain at that level so that he should then surface or rise promptly.

The foregoing is accomplished by means of rod 81 which is vertically adjustable in the device. It will be recalled that rear end 65 of lever 34 abuts against rod 81 so as to limit the rear end of lever 34 in its downward movement. By limiting such end of the lever 34, the front or acting end is correspondingly limited and the valve pin 32 may not be pressed down to the completely open position.

amuse Rod 81 is provided with a fixed transverse pin 85 which rests upon threaded bushing 86. The top face of threaded bushing 86 is formed with diametrical grooves 87 and 88. Grooves 87 are shallow and aligned and constitute a relatively raised level while grooves 88 are somewhat deeper. Transverse pin 85 may rest in either grooves 87 or grooves 88. When it rests in grooves 87, the rod 81 is obviously at a higher level and the movement of lever 34 is accordingly limited to produce the normal restriction. However, when rod 81 is turned 90 the pin falls into the deeper grooves 88 so as to free the levers to travel their normal stroke. This produces the maximum opening in the path between the chambers 21 and 22 and the theretofore inadequate pressure becomes suitable to permit normal breathing.

Rod 81 is enlarged at its outer shaft portion 90 and.

extends outwardly of threaded bushing 86 so as to be outwardly of the body 14. Shaft 90 is terminated by a manually actuable knob 91. Knob 91 is provided with an annular flange 92 and head 93 of bushing 86 is provided with a central depression. Between the central depression'and flange 92 is disposed a short length of resilient rubber tubing 94, the function of which is to permit the shaft 90 and rod 81 to be depressed downwardly for actuating the transverse pin 85 without permitting water to flow into the chamber and providing a spring action maintaining pin 85 against the top face of bushing 86. Thus, when it is desired to switch the pin 85 from groove 87 to groove 88, knob 91 is pressed inwardly against the action of rubber tube 94 so as to push pin 86 outwardly whereupon knob 91 may be rotated 90 to cause the pin 85 to fall into the deeper groove assisted by the spring action of tube 94 which normally tends to urge the rod 81 downwardly except for the inhibiting action of the pin 85 in the restricting position and effectively release the lever 34.

It is desirable to permit a preliminary adjustment of the air reserve device. This is effected by means of the screw threaded bushing 86 which can be set to any predetermined position and then locked by means of nut 95.

The regulator is aifixed in a conventional manner to the output valve of a tank of compressed air by means of the yoke 96 which encircles such output valve as described in my prior application, the screw 97 serving to tighten the connection. In this way, the compressed air may be directed through perforated disk 35 and into the regulator interior as above described.

The device is operated in the following manner:

After having affixed the regulator of the tank on the divers back, and having inserted the mouthpiece of the tube in his mouth, the diver is prepared to descend. He will preliminarly actuate knob 91 by depressing it against the spring action of tube 94 so as to position pin 85 into the shallower grooves 87 and effectively raise rod 81 upwardly to limit the action of the levers. Thereafter, when the diver descends, the surrounding water thereupon enters openings 52 and acts upon diaphragm 43 to depress it so as to operate levers 61 and 34. The air pressure in the tank being high at this time, the restricted opening in the path between the chambers 21 and 22 does not interfere with a required volume of air to suit the divers requirements and allow normal breathing.

When the air pressure drops to a low enough point, determined by the initial setting of threaded bushing 86, breathing will become difiicult because not enough pressure is available to supply a normal lung-full of air in the normal length of time. This will cause the diver to labor with his breathing because his lungs are not filling rapidly enough. This point will be reached sooner when the diver is at a lower depth because he requires greater pressure of air at this point and it is not being supplied. It can thus be appreciated that the same air pres sure would still suffice at a higher water lever but it is insufficient at the low level, thus making it commensurate with the depth reached. When the diver notes his breathing diificulty, he will release the reserve device by rotating knob 91 so as to lower rod 81 and permit the full stroke of the levers. This will open the restriction and restore normal breathing. Of course, the diver will then begin to ascend since he is aware that he only has a limited amount of air left.

It will further be noted that in addition to the advantage of the reserve device operating in accordance with depth,

it further automatically compensates for a person with" a high intake rate since he will tend to depress the levers further at each breath thereby making it necessary to open the reserve sooner. Another important feature is that the reserve will also function in an improved manner in the event of over-exertion where the diver is breathing deeply. Obviously, under these conditions, a fixed amount of air would not serve him for the same time as when he is breathing at a normal slow rate but the reserve device will respond sooner.

The regulator of the instant invention further embodies the advantages set forth in my prior application in that exhaust channel or chamber 15 is totally enclosed against the discharge of exhaust air save for outlet opening 17 which is itself not subjected to water pressure save through openings 52 of cup 50 so that the air exhaust path is through opening 17 and openings 52. In the position illustrated where the diaphragm is at a higher vertical level than the exhaust valve, the openings 52 are higher than the diaphragm. In a reverse position, i. e., the exhaust valve above the diaphragm (as may occur when a diver is on his back) the openings 52 are below the diaphragm and the exhaust valve cannot be reached by water pressure except through such openings 52. In other words, the exhaust valve 13 is subjected to a water pressure which is always greater than that of diaphragm 43 notwithstanding any position of the regulator. This prevents any spontaneous leaking of compressed air through the exhaust valve and further permits the main valve structure to be as sensitive as desired. The reason therefore is it is not necessary to provide an artificial, predetermined barrier to easy breathing since the position of the exhaust valve cannot of itself operate the valve and produce air flow in any event.

The specific limiting means shown and described operates upon the lever structure shown but the same general principle can be employed and will produce similar advantages when used with other lever mechanisms and without acting directly upon the lever structure. For example, in Figure 10 is shown a collar which may be interposed between the air pressure tank outlet valve and the perforated disk 35. Collar 100 is formed with a central longitudinal opening 101 and a transverse annular chamber 102. Opening 101 is of a cross-sectional area equivalent to the largest effective area of throat 23 so that it can never operate as an air flow restriction.

Within chamber 102 is rotatably disposed a valve stem 103 having two sets of openings therethrough. Opening 104 is adapted to register with opening 101 and is of the same cross-sectional area so as to constitute a full continuation thereof. On the other hand, opening 105 is a constricted opening disposed 90 away from opening 104. Both openings extend completely through stem 103 which fits snugly in chambr 102. Knob 106 is turnable so as to inject either opening into the air stream. Thus, when opening 104 is in alignment with opening 101, maximum flow exists whereas when opening 105 is in alignment, restricted fiow exists. The extent of restriction will be predetermined to produce respective flows as in the previous embodiment.

The operation of the modification will be obvious, the user first rotating the valve stem to a position where the smaller opening 105 is in alignment with 101 so as to limit the flow of air before it gets to valve pin 32. When the supply of air becomes insufficient to meet the divers demand as above set forth, he will rotate knob 106 90 to effectively insert larger opening 104 in the air stream.

Suitable indicia on the knob and collar may be employed as a guide.

What is claimed is:

1. In a breather regulator comprising a chamber, movable means in said chamber exposed to the surrounding fluid media through said chamber and movable in response to the pressure of said surrounding fluid media, motion transmitting means actuated by said movable means, means defining an inlet path for admitting air under pressure into said chamber, said inlet path including an air flow opening, and a valve member in said air flow opening and operating to adjust the effective extent of opening thereof so as to control. the flow of air therethrough, said motion transmitting means acting upon said valve member in response to said movable means so as to admit air under pressure into said chamber, and to restore said movable means to a normal, valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user and correspondingly withdrawn from restoring action on said movable means whereby said valve member opens in response to the pressure of said surrounding fluid media, limiting means for limiting the effective extent of opening of said air flow opening so as to limit the flow of air upon which said valve member can act in response to said motion transmitting means, and externally accessible means to control said limiting means for rendering said limiting means at least partially ineffective so as to produce a larger effective extent of opening of said air flow opening, said motion transmitting means being a lever structure, said limiting means comprising a member bearing against said lever structure and preventing full lever action thereof, said last-named member including a spring member normally urging said limiting means to a non-limiting position, and said control means inhibiting action of said spring member.

2. A device according to claim 1 and wherein said limiting means is a rod which is actuable externally of said chamber to either of two alternative positions, one position being that which limits action of said lever structure and the other position being that which permits relatively unimpeded action of said lever structure.

3. In a breathing regulator comprising a body, a chamher in said body, a diaphragm in said chamber, said diaphra gm being flexible and being exposed to the surrounding fluid media through said chamber whereby said diaphragm may be deflected by the pressure of surrounding fluid media, lever means actuated by said diaphragm deflection, an inlet member for admitting air under pressure therethrough and into said chamber, said inlet member having an air flow opening and a valve member in said air flow opening and operating to adjust the effective extent of opening thereof so as to aflcct the flow of air therethrough, said lever means acting against said valve member in response to diaphragm deflection so as to admit air under pressure into said chamber, and to restore said diaphragm to a normal. valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user, and correspondingly withdrawn from restoring action on said diaphragm whereby said valve member opens in response to the pressure of said surrounding fluid media, limiting means for initially limiting the eflective extent of opening of said air flow opening so as to limit the flow of air upon which said valve member can act in response to said lever means, and externally accessible means to manually adjust said limiting means to a fixed and predetermined relatively nondimiting position so as to produce a larger effective extent of opening of said air flow opening.

4. A device according to claim 3 and wherein said limiting means abuts said lever means so as to limit movement thereof.

8 5. A device according to claim 4 and wherein said lever means comp-rises a first rockable lever one end of which is substantially downwardly depressed by said diaphragm deflection and the other end of which thereupon rocks in a substantially downward direction, a second lever actuated at one end thereof by said rocking action of said rockable lever and operating said valve member at the other end of said second lever, said limiting rod bearing against said one end of said second lever and being vertically adjustable for intercepting the movement of said one end at different vertical levels and limiting the action of said second lever on said valve member.

6. A device according to claim 5 and including a vertically adjustable screw upon which the extreme other end of said second lever rests, said valve member including a movable valve body positioned adjacent to and inwardly of'said extreme other end of said second lever.

7. A device according to claim 6 and includinga screwthreaded bushing in said body, a shaft integral with said rod and slidable in said bushing, a transverse pin on said shaft, the face of said bushing being within said body and having a pair of high and low rest positions for said pin whereby said rod may be maintained in its higher or lower vertical levels.

8. A device according to claim 7 and including a manually actuable knob on said shaft, and a rubber tube etween said bushing and said knob for providing a spring action normally maintaining said pin against said face of said bushing and maintaining a water tight sliding flt of said shaft.

9. In a breathing regulator comprising a body, a chamber in said body, a flexible diaphragm in said chamber, a cap for said body having upper openings formed therethrough so as to expose the diaphragm to the surrounding fluid media whereby the diaphragm may be deflected by the pressure of surrounding fluid media, lever means actuated by said diaphragm deflection, said lever means comprising a first rockable lever one end of which is substantially downwardly depressed by said diaphragm deflection and the other end of which thereupon rocks in a substantially downward direction, a second lever actuated at one end thereof by said rocking action of said rockable lever and operating said valve member at the other end of said second lever, an inlet member for admitting air under pressure therethrough and into said chamber, said inlet member having an air flow opening and a valve member in said air flow opening and operating to adjust the eitective extent of opening thereof so as to atfect the flow of air therethrough, said second lever bearing against said valve member in response to diaphragm deflection for admitting air under pressure through said air flow opening and into said chamber, and to restore said diaphragm to a normal valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user, and correspondingly withdrawn from restoring action on said diaphragm whereby said valve member opens in response to the pressure of said surrounding fluid media, a lever action limiting rod disposed against said one end of said second lever and limiting actuation thereof so as to accordin ly limit the maximum valve opening position of said valve member, and means to manually adjust said limiting rod externally of said body to a non-limiting position so as to permit said valve member to assume its maximum valve opening position.

10. In a breathing regulator comprising a body, a chamber in said body, a diaphragm in said chamber, said diaphragm being flexible, a cap for said body having openings formed therethrough so as to expose the diaphragm to the surrounding fluid media through said chamber whereby said diaphragm may be deflected by the pressure of surrounding fluid media, lever means actuated by said diaphragm deflection, an inlet member aver ps for admitting air under pressure therethrough and into said chamber, said inlet member having an air flow opening and a valve member in said air flow opening and operating to adjust the effective extent of opening thereof so as to affect the flow of air therethrough, said lever means acting against said valve member in response to diaphragm deflection so as to admit air under pressure into said chamber, and to restore said diaphragm to a normal valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user, and correspondingly withdrawn from restoring action on said diaphragm whereby said valve member opens in response to the pressure of said surrounding fluid media, limiting means for initially limiting the effective extent of opening of said air flow opening so as to limit the flow of air upon which said valve member can act, externally accessible means to manually adjust said lirnitin' means to a fixed and predetermined relatively non-limiting position so as to produce a larger effective extent of opening of said air flow opening, an air exhaust chamber formed in said body, an exhaust valve in said exhaust chamber, said exhaust valve being vertically spaced from said diaphragm, an air exhaust path for said exhaust chamber comprising an air outlet in said exhaust chamber communicating With said cap openings, said exhaust chamher being otherwise totally enclosed against the discharge of exhaust air, said cap openings being at least at the vertical level of said diaphragm when the regulator is in a position where the diaphragm is at a higher vertical level than said exhaust valve.

11. A device according to claim 10 and wherein said cap openings are on the upper face thereof and above the vertical level of said diaphragm in said position of the regulator.

12. A device according to claim 11 and wherein said lever means comprises a first rockable lever one end of which is substantially downwardly depressed by said dia phragm deflection and the other end of which thereupon rocks in a substantially downward direction, a second lever actuated at one end thereof by said rocking action of said rock-able lever and operating said valve member at the other end of said second lever, said limiting means comprises a rod bearing against said one end of said second lever and being vertically adjustable for intercepting the movement of said one end at different levels and limiting the action of said second lever on said valve member.

13. A device according to claim 12 and including a vertically adjustable screw upon which the extreme other end of said second lever rests, said valve member including a movable valve body positioned adjacent to and inwardly of said extreme other end, said limiting means further comprising a screw-threaded bushing in said body, a shaft integral with said rod and slidable in said bushing, a transverse pin on said shaft, the face of said bushing being within said body and having a pair of high and low rest positions for said pin whereby said rod may be seated in higher or lower vertical levels.

14. In a breathing regulator comprising a body, a chamber in said body, a flexible diaphragm in said chamber, a cap for said body having upper openings formed therethrough so as to expose the diaphragm to the surrounding fluid media whereby the diaphragm may be deflected by the pressure of surrounding fluid media, lever means actuated by said diaphragm deflection, said lever means comprising a first rockable lever one end of which is substantially downwardly depressed by said diaphragm deflection and the other end of which thereupon rocks in a substantially downward direction, a second lever actuated at one end thereof by said rocking action of said rockable lever and operating said valve member at the other end of said second lever, an inlet member for admitting air under pressure therethrough and into said chamber, said inlet member having an air flow opening and a valve member in said air flow opening and operating to adjust the effective extent of opening thereof so as to afiect the flow of air therethrough, said second lever bearing against said valve member in response to diaphragm deflection for admitting air under pressure through said air fiow opening and into said chamber, and to restore said diaphragm to a normal valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user, and correspondingly withdrawn from restoring action on said diaphragm whereby said valve member opens in response to the pressure of said surrounding fluid media, a lever action limiting rod disposed against said one end of said second lever and limiting actuation thereof so as to accordingly limit the maximum valve opening position of said valve member, means to manually adjust said limiting rod externally of said body to a fixed and predetermined relatively non-limiting position so as to permit said valve member to assume its maximum valve opening position, a vertically adjustable screw upon which the extreme other end of said second lever rests, said valve member including a movable valve body positioned adjacent to and inwardly of said extreme other end and a screw-threaded bushing in said body, a shaft integral with said rod and slidable in said bushing, a transverse pin on said shaft, the face of said bushing being within said body and having a pair of high and low rest positions for said pin whereby said rod may be seated in higher or lower vertical levels pursuant to sliding action of said shaft.

15. In a breathing regulator comprising a chamber, movable means in said chamber exposed. to the surrounding fluid media through said chamber and movable in response to the pressure of said surrounding fluid media, motion transmitting means actuated by said movable means, means defining an inlet path for admitting air under pressure into said chamber, said inlet path including an air flow opening, and a valve member in said air flow opening and operating to adjust the effective extent of opening thereof so as to control the flow of air therethrough, said motion transmitting means acting upon said valve member in response to said movable means so as to admit air under pressure into said chan1 her, and to restore said diaphragm to a normal valve closing position against the action of said surrounding fluid media, means defining an outlet path in communication with said chamber whereby said air under pressure may be inhaled by a user, and correspondingly withdrawn from restoring action on said diaphragm Where-- by said valve member opens in response to the pressure of said surrounding fluid media, air flow limiting means for restricting the maximum flow of air through said inlet path so as to limit the flow of air upon which said valve member can act, and externally accessible means to control said limiting means for rendering said limiting means inelfective by removing the restricting effects thereof to produce a greater air flow.

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